…this will no doubt come and bite me in the ass later…
But mine has been surprisingly OK. 320D M-sport tourer, so it's got fairly silly tyres on. Only had it 2 months, so RWD is new to me. It's a bugger to get going on slippy surfaces (I live on a hill), but once it's moving, its pretty well behaved, and it seems to be much better behaved in corners than anything else I've tried on snow, simply because if the front starts sliding, then the back can be made to overcompensate so you still end up pointing where you want to go. It's mostly a question of turning in a bit early, being smooth, keeping the power on and being confident.
Where we stayed at christmas was up a hill accessed by a private drive about 1/2 mile long and sheet ice, accessed from an equally ungritted minor road. I was one of only 2 non-4x4s to get up there (making the turn through the gateposts at the top was a little hairy though). A Volvo failed to do it which did make me feel slightly smug.
That all said, I wouldn't dream of trying to drive it on busy roads in this weather, simply because of the number of other cars around. With the best will in the world, I'd end up having to stop somewhere I didn't want to and then would struggle to get going again. That and it's far more fun to ride the bike!